Question 1

How many gallons of wastewater (approximately) can be held in a rectangular wet well with the following dimensions: 10-foot (ft) liquid depth, 12 ft wide, and 15 ft long?

Accepted Answer

A) 240 gallons 
B) 1,800 gallons 
C) 2,400 gallons 
D) 13,464 gallons 
A) 240 gallons 
B) 1,800 gallons 
C) 2,400 gallons 
D) 13,464 gallons D

Question 2

What is the change in elevation between the upstream invert and the downstream invert of a 400-foot (ft) section of 8-inch diameter sewer pipe set at a 4.5% slope?

Accepted Answer

A) <2 ft 
B) 4.5 ft 
C) 18 ft 
D) Not enough information provided 
A) <2 ft 
B) 4.5 ft 
C) 18 ft 
D) Not enough information provided C

Question 3

In a typical municipal wastewater treatment plant, what is the normal retention time range for primary sludge in a gravity thickener, depending on temperature?

Accepted Answer

A) Less than 1 day 
B) 1 to 2 days 
C) 2 to 3 days 
D) More than 3 days 
A) Less than 1 day 
B) 1 to 2 days 
C) 2 to 3 days 
D) More than 3 days B

Question 4

Raw wastewater can potentially contain which of the following?

Accepted Answer

A) Pathogens 
B) Microconstituents 
C) Both A. and B. 
D) None of the above 
A) Pathogens 
B) Microconstituents 
C) Both A. and B. 
D) None of the above

Question 5

In a typical municipal wastewater treatment plant, at which point in the treatment process is the influent flow meter located?

Accepted Answer

A) Prior to pretreatment screening 
B) Between screens and grit removal 
C) Between grit removal and lift pumps 
D) Between lift pumps and primary treatment units 
A) Prior to pretreatment screening 
B) Between screens and grit removal 
C) Between grit removal and lift pumps 
D) Between lift pumps and primary treatment units

Question 6

What is considered to be the scouring velocity of gravity sanitary sewers, in feet per second (ft/sec)?

Accepted Answer

A) 1 ft/sec 
B) 2 ft/sec 
C) 4 ft/sec 
D) 4.5 ft/sec 
A) 1 ft/sec 
B) 2 ft/sec 
C) 4 ft/sec 
D) 4.5 ft/sec

Question 7

Why would wastewater treatment plant effluent need to be dechlorinated?

Accepted Answer

A) Reduce the toxicity due to chlorine residuals 
B) Reduce odors 
C) Increase nutrients released to the receiving stream 
D) None of the above 
A) Reduce the toxicity due to chlorine residuals 
B) Reduce odors 
C) Increase nutrients released to the receiving stream 
D) None of the above

Question 8

If septicity occurs in a gravity thickener, which of the following actions would not likely improve the situation?

Accepted Answer

A) Aerate the thickener feed 
B) Add chlorine or hydrogen peroxide 
C) Decrease the underflow pumping rate 
D) Decant the thickener feed 
A) Aerate the thickener feed 
B) Add chlorine or hydrogen peroxide 
C) Decrease the underflow pumping rate 
D) Decant the thickener feed

Question 9

What is the primary purpose of the use of lift stations in a municipal wastewater collection system?

Accepted Answer

A) Minimize easement requirements for an alignment 
B) Increase the capacity of a sewer line 
C) Move wastewater from a lower to higher elevation 
D) Increase velocity of the wastewater traveling through a sewer line 
A) Minimize easement requirements for an alignment 
B) Increase the capacity of a sewer line 
C) Move wastewater from a lower to higher elevation 
D) Increase velocity of the wastewater traveling through a sewer line

Question 10

Typically, what are assumed to be appropriate sludge storage facilities for mechanical wastewater treatment plants?

Accepted Answer

A) Drying beds 
B) Lagoons 
C) Tanks 
D) All of the above 
A) Drying beds 
B) Lagoons 
C) Tanks 
D) All of the above

How many gallons of wastewater (approximately) can be held in a rectangular wet well with the following dimensions: 10-foot (ft) liquid depth, 12 ft wide, and 15 ft long?

What is the change in elevation between the upstream invert and the downstream invert of a 400-foot (ft) section of 8-inch diameter sewer pipe set at a 4.5% slope?

In a typical municipal wastewater treatment plant, what is the normal retention time range for primary sludge in a gravity thickener, depending on temperature?

Raw wastewater can potentially contain which of the following?

In a typical municipal wastewater treatment plant, at which point in the treatment process is the influent flow meter located?

What is considered to be the scouring velocity of gravity sanitary sewers, in feet per second (ft/sec)?

Why would wastewater treatment plant effluent need to be dechlorinated?

If septicity occurs in a gravity thickener, which of the following actions would not likely improve the situation?

What is the primary purpose of the use of lift stations in a municipal wastewater collection system?

Typically, what are assumed to be appropriate sludge storage facilities for mechanical wastewater treatment plants?

Earth Retention

Earth Structures

Earthworks

Estimation

Foundations

Hydraulics Closed

Hydraulics Open

Hydrology

Material Mechanics

Material QC

Member Design

Scheduling

Soil and Materials

Soil Mechanics

Struct Loading

Struct Materials

Struct Analysis

Subsurface

Transportation

Water Treatment

Filters

Exam 20: Waste Water

How many gallons of wastewater (approximately) can be held in a rectangular wet well with the following dimensions: 10-foot (ft) liquid depth, 12 ft wide, and 15 ft long?

What is the change in elevation between the upstream invert and the downstream invert of a 400-foot (ft) section of 8-inch diameter sewer pipe set at a 4.5% slope?

In a typical municipal wastewater treatment plant, what is the normal retention time range for primary sludge in a gravity thickener, depending on temperature?

Raw wastewater can potentially contain which of the following?

In a typical municipal wastewater treatment plant, at which point in the treatment process is the influent flow meter located?

What is considered to be the scouring velocity of gravity sanitary sewers, in feet per second (ft/sec)?

Why would wastewater treatment plant effluent need to be dechlorinated?

If septicity occurs in a gravity thickener, which of the following actions would not likely improve the situation?

What is the primary purpose of the use of lift stations in a municipal wastewater collection system?

Typically, what are assumed to be appropriate sludge storage facilities for mechanical wastewater treatment plants?

Earth Retention

Earth Structures

Earthworks

Estimation

Foundations

Hydraulics Closed

Hydraulics Open

Hydrology

Material Mechanics

Material QC

Member Design

Scheduling

Soil and Materials

Soil Mechanics

Struct Loading

Struct Materials

Struct Analysis

Subsurface

Transportation

Water Treatment

Filters